The vegetation types and distributional characteristics of the forest vegetation on Mt. Ilwol were investigated by the Z-M school method. Geographical distribution of the vegetation was a central/montane(CEMO) type of the Korean Peninsula subtype. The forest was classified into five vegetation units: Artemisio-Quercetum mongolicae (Artemisio-Quercetum typicum subass. nov., Artemsio-Quercetum pinetosum dens~florae subass. nov. ). Lychno-Quercetum mongolicae (Lychno-Quercetum Calamagrostetosum arundinaceae subass. nov.. Lychno-Quercetum ligularetosum f~scherii subass. nov.), Fraxinus rhynchophylla community, Quercus variabilis community and Larix leptolepis afforestation. Species with percentage constance degree more than 61% are Quercus mongolica (89.5%, V), Lespedeza maximowiczii (73.7%, IV), Isodon japonicus(73.7%, IV), Fraxinus rhynchophylla (68.%, IV), Arlemisia stolonifera (65, 8%, IV), etc. Artemisio-Quercetum mongolicae was chiefly distributed on the ridge lines of low altitudes (570~700m) and on the ground with exposed rocks in sloping surface (800~1, 000m). Both Fraxinus sievoldiana and Rhododendrou schlippenbachii of the Artemisio-Quercetum mongolicae showed a predominant condition all over the subtree and shrub layers. Of Artemisio-Quercetum pinetosum densifloraes, Pinus densiflora becomes powerful over the tree layer and, on the other hand, Quercus mongolica over the subtree layer. Lychno-Quercetum mongolicae was distributed somewhat on the humid region of the high altitude area (840~1.200m). Fraxinus rhynchophylla community was chiefly distributed in the vicinity of the ravines. Quereus rariabilis community was distributed at subxeric slope on southeast side of the mountain. Larix leptolepis has been reforested at the ecotone between Artemisio-Quercetum mongolicae and Lychno-Quercetum mongolicae. Percentage cover degrees of the subtree layer In Lychno-Quercetum mongolicae, Quereus rariabilis community and Larix leptolepis afforestation were relatively low, 15.3%, 5% and 2.5%, respectively.The contents of moisutre and organic matter in the soil were much higher in Luchno-Quercetum monogolicae and Larix leptolepis afforestaion than in the other communities. Contents o Ca, Mg, K and the available phosphorus were relaively high compared with forests of the other area. This result seems to be influenced by a forest fire. As the altitude increases, the moisure content in the forest soil also increases.

The nitrogen assimilation rate of nitrogenous nutrients by reservior phytoplankton was masured in the in situ condition in the euphotic layer of Lakes Soyang, Chuncheon and Uiam located on the upper reaches of the North Han River System in August, 1983, Korea. The assimilation rate of ammonia, nitrate and urea nitrogen in surface water was 13, 2 and at. $N{\cdot}m^{-3}{\cdot}(12:10~18:15)^{-1}$ in Lake Soyang, 325, 27 and at. in Lake Chuncheon, and 174, 12 and at. in Lake Uiam. Ammonia and urea were perferntially utilized by reservoir phytoplankton. The dark/light ratios of nitrate assimilation were much lower than those of ammonia and urea assimilation of nitrate showed little contribution. The primary productuin was estimated as 59mg and 6.9mg in Lake Spyang, 217mg and 26mg in Lake Chuncheon, and 110mg and 13mg in Lake Uiam, with production ratios of 8.6, 8.4 and 8,4, respectively. The turnover time o ammonia and urea in the upper euphotic layer was 2 to 47 days and 4 to 38 days, respectively. Nitrate required much longer periods. In the euphotic layer of reservoirs, ammonia and urea played signigicant roles in the biogeoKDICical nitrogen metabolism.

To study allelopathic porential of naturally occurring substances emitted from Pinus koraiensis, the effects of water exrracts and volatile substances of the tree on callus induction and bacterial culture were examined. The induction and growth of callus were inversely proportional to the concentration of the extracts and of the essential oils supplemnted to Murashige and Skoog's media. However, low concentration(5μl/l) of essential oil promoted callus growth. In germiculture of several bavteria, the extracts of Pinus koraiensis markedly showed the inhibitory effects on bacterial growth. It was, therefore, confirmed that the KDICical substances of Pinus koraiensis tree clearly showed that biological toxic activity at high concentrations.

A phytosociological study of forest vegetation of Mt. Kaya was carried out from August 1988 to September 1992. The forest vegetation of the area was classified into 3 communities (Quercus monogolica community, Lindera erythrocarpa community, Pinus densiflora community) and 3 subunits (Rhododendron mucronulatum subunit, Platycarya strobilacea subunit, typical subunit of Pinusdensiflora community). The Pinus densiflora community was located at the lower altitudes (100~300m) than those of other communities. The Lindera erythrocarpa community was located at the upper altitude (500m). Most of the inverstigated area were occupied by the secondary forest of Pinus densiflora community in the actual vegetation map and the profile diagram, suggesting that it was frequently destroyed by human interference

Stands profiles, yearly changes in growth of annual rings, age and diameter structure, and spatial distribution pattern of individuals in the Pinus densiflora stands around the Yeocheon industrial complex were investigated. Growth of annual ring in Pinus densiflora, which survived when vegetation of this area was damaged by air pollutants, was suppressed for about 10 years since 1974 when factories in this area began to operate, but since then such suppressed growth tended to be recovered. It was supposed that the suppresed growth was originated from air pollution and that improvement of growth since the suppressed period was due to the release from competition with them by death of neighbouring trees and the resuction of the amount of air pollutants. Physiognomy of Pinus densiflora stands showed mosaic pattern composed of different patches. Spatial distribution pattern of individuals an stand profiles were similar to those of Pinus densiflora stands regenerated after natural and artificial disturbances. In an age distribution diagram, age of Pinus densiflora population ranged from 1 to 33 years, Among these individuals were recrited corresponded to the suppresed period of growth of annual ring in Pinus densiflora survived when the vegetation was damaged by air pollution. On the other hand, from the result of analysis of frequency distribution diagram of diameter, it was postulated that even if whis Pinus densiflora community can be maintained as it is for the time being, it might be changed to Quercus community with the lapse of time.

Stands profiles, yearly changes in growth of annual rings, age and diameter structure, and spatial distribution pattern of individuals in the Pinus densiflora stands around the Yeocheon industrial complex were investigated. Growth of annual ring in Pinus densiflora, which survived when vegetation of this area was damaged by air pollutants, was suppressed for about 10 years since 1974 when factories in this area began to operate, but since then such suppressed growth tended to be recovered. It was supposed that the suppresed growth was originated from air pollution and that improvement of growth since the suppressed period was due to the release from competition with them by death of neighbouring trees and the resuction of the amount of air pollutants. Physiognomy of Pinus densiflora stands showed mosaic pattern composed of different patches. Spatial distribution pattern of individuals an stand profiles were similar to those of Pinus densiflora stands regenerated after natural and artificial disturbances. In an age distribution diagram, age of Pinus densiflora population ranged from 1 to 33 years, Among these individuals were recrited corresponded to the suppresed period of growth of annual ring in Pinus densiflora survived when the vegetation was damaged by air pollution. On the other hand, from the result of analysis of frequency distribution diagram of diameter, it was postulated that even if whis Pinus densiflora community can be maintained as it is for the time being, it might be changed to Quercus community with the lapse of time. Regeneration; Pinus densiflora; Air pollution; Annual ring; Age structure; Diameter structure; Quercus spp. In these analyses, factors for individual recognition and species recognition were suggested.

Effects of relative light intensity and N, P fertilization on the growth and ramet dynamics of the rhizomatous plants, Arundinella hirta, Miscanthus sinensi and Spdiopogon sibiricus were studied in Chuncheon, Kangweon-Do. Ramets emerged in one pulse a year, withered in one pulse at the end of the growing season in M. sinensis and S. sibircus stands, while the birth and death pulse in A. hirta stands were two times. Total births of ramet were 9 times and 3.6 times greater in the unshaded fertilized stands of A. hirta and M. sinensis than in the shaded, However, those of S.sibiricus were 2.1 times greater in the shaded stands. Flowering rates of A. hirta, M.sinensis and S.sibiricus I the unshaded fertilized stands were 1.8, 2.7 and 1.04 times greater than in the shaded unfertilized stands, respectively. Height of ramets of A. hirta and M.sinensis were the hightest in the unshaded fertilized stands. However, that of s.sibiricus was the highest in the shaded fertilized stand. Aboveground production of A.hirta in the fertilized stand was 2.4 times greater in the unshaded stand than in the shaded one. Results of inflorescence frequency, shoot height and the ratio of aboveground to belowground were smiliar to the total births. The added fertilizer markedly increased the ramet density and the shoot productivity of three rhizomatous plants, especially of A. hirta.

To make clear the interspecific relation through competiton and affinities the forest vegetation of Yangjinam area, Mt. Palgong was analysed. By the calculation of based on the vegetation data collected from 125 quadrats of 12 sites, the component species of the study area were divided into 1 distinct group and 2 less distinct groups. In contrast, the analysis based on TWINSPAN and DECORANA showed that 4 group could be separated. These were Quercus monogolica-Pinus densiflora community, Quercus monogolica-Corylus sieboldiana community.

To elucidate ecophysiological factors affecting nutural distribution of evergreen broad-leabed trees in Danohad National Marine Park, water potential, relative water content and photosynthetic activities of 4 species, Cammellia japonica, Machilus thunbergii, Castanopsis cuspidata var.sieboldii and Quercus acuta, were potential began to decrease from 07:00h to its minimum value at 13:00h for C. cuspidata var. sieboldii (-14.3bar) and Q. acuta (-19.4bar) at 16:00 h for M. thunbergii(-17.0bar) and at 19:00 h for C. japonica (-14.5bar), and these showed similar trends to relative water content. Photosynthetic activities of 4 species began to increase from 7:00 h and reached maximum values before their minimum values of water potential occureed. Optimum temperature renges of photosynthetic activities was for C. japonica - M. thunbergii and for C. cuspidata var. sieboldii Quercus acuta.Q.acuta had the highest light saturation point of and C. japonica the lowest of . Water potential of 4 species subjected to water stress, began to decrease after 1st day of drought and after 21th day of drought, those of C. japonica, M. thunbergii, C. cuspidata var. sieboldii and Q. acuta decreased to species began to decrease after 7th day of drought and after 21th day, those of M. thunbergii, C. cuspidata var. sieboldii and Q. acuta were dropped to about 50% and C. japonica 83.5%. Photosynthetic activity of 4 specie began to decline in the order of C. cuspidata var. sieboldii, Q.acuta, C. japonica and M. thunbergii after 10th day of drought. These results suggest that the segregated disributions of C. japonica - M. thunbergii on vally positions and C. cuspidata var. sieboldii - Q. acuta on slopes were associated with different responses of water status and photosyntheties to their environment.

Pollen analysis on a 320cm core collected from paengsung area (36°56′50"N, 127°03′10"E) in southwesterm korea was carried out to investigate the changes in past climate and vegetation in that area. In this research it was found that pollen zones are divided into two layers of substage IIb and IIc. Pollen zone IIb, the lower layer, was dominated by high percentages of deciduous broadleaved trees such as alnus, Quercus, Corylus, Betula, Carpinus and Salix. Trapa, Typhaceae and Nymphaceae growing in wet habitat and Chenpodiaceae were pornounced amont the nonrboreal pollens. At that time, it seems that it was warmer and more humid than present. In pollen zone IIc, the upper layer, pollen of Pinun was dominant and those of Artemisia, Gramineae, Compositae, Cyperaceae and spore increased while of Quercus, Betula and Nymphaceae decreased. It is supposed that the climate of this zone was drier that the lower laywer.